-
the majority of braking forces going through the front and its spokes?
The same is true with rim brakes, the main difference with discs is that the front wheel gets asymmetrically loaded under braking. You can mitigate this by making the hub shell very stiff in torsion (large diameter barrel) as many hubs do. Apparently 20H front disc hubs are fine for relatively light and skilful riders, but wheel manufacturers can't rely on limiting sales to such people so go for 24H.
Is this true with disc brakes with the majority of braking forces going through the front and its spokes?
edit. Saying that I have a cheapo set of wheels off of a specialised which are laced 2x/radial on the front, so only 14x spokes transmitting braking forces...